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  Device for patterning workpiecesUSPTO Application #: 20080106568Title: Device for patterning workpieces Abstract: The invention relates to a device (1) for patterning workpieces (2), which preferably consist at least partially of wood, wood materials or the like, having an ink-jet printing means (10) having a plurality of nozzles (12) from which drops of ink can be expelled, a workpiece carrier means (20) for carrying the workpiece (2) to be patterned, a conveyor device for bringing about a relative movement between the workpiece (2) to be patterned and the printing means (10). The device according to the invention is characterised in that it further has at least one image detection sensor (46). (end of abstract) Agent: Baker Botts L.L.P. - New York, NY, US Inventors: Ludwig Albrecht, Karl Frey, Achim Gauss USPTO Applicaton #: 20080106568 - Class: 347 19 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20080106568. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001]The invention relates to a device for patterning workpieces, which preferably consist at least partially of wood, wood materials or the like, according to the preamble of claim 1. PRIOR ART [0002]A device of the type mentioned at the outset is known, for example, from DE 100 31 030 B4 and has sensors for roughly detecting the contour and thickness of the workpieces to be imprinted which are attached to a conveyor device or to a portal. Nevertheless, it has been found that the workpieces imprinted using a device of this type often have a distorted, smudged printed image or else a printed image displaying defects and colour variations. [0003]Furthermore, European patent application EP 05 009 326.9, which was filed by the Applicant and has not yet been published, also relates to a device according to the preamble of claim 1. PRESENTATION OF THE INVENTION [0004]The object of the present invention is therefore to provide a generic device for patterning workpieces that allows an improved printed image quality. [0005]According to the invention, this object is achieved by a device according to claim 1 and a method according to claim 7. Particularly advantageous developments of the invention are specified in the dependent claims. [0006]The underlying idea of the invention is that of basing the printing process, by targeted preprocessing and/or postprocessing, on completely new information. For this purpose, provision is made for the device according to the invention also to have at least one image detection sensor. The provision of at least one image detection sensor opens up entirely new possibilities for controlling and optimising the printing process. It is thus possible, for example, to determine using the image detection sensor the precise position of the workpiece relative to the printing means even before the printing process ("preprocessing"). This allows distortion and smudging of the printed image, which are caused by inadequate relative positioning, to be avoided or minimised. An "overspray", i.e. printing being carried out beyond a free edge of the workpiece and ink mist being deposited on an adjacent surface of the workpiece, can also be effectively prevented. [0007]However, even after a printing process (or before a subsequent printing process), the image detection sensor provided in accordance with the invention can be effectively used to analyse the workpiece surface. For example, the image sensor can be used to carry out an analysis of the workpiece surface with regard to possible defects, colour variations or the like in order to check and, for example, to maintain, to clean, to adjust, etc. the printing means on this basis. [0008]These and further possible applications of the image detection sensor allow the quality of the printed image to be greatly increased over the prior art. The term "image detection sensor" refers in this case at least to any means which operates on an optical basis and supplies information about the image formed (which may or may not be visible to the human eye), so use may be made of a broad range of means including, for example, spectrophotometers with or without (RGB) filters. [0009]In order to be able efficiently to implement the above-described and further possible applications of the image detection sensor to improve the quality of the printed image, a development of the invention provides for the device further to have a control means which is connected to the at least one image detection sensor and the ink-jet printing means. [0010]Within the scope of the present invention, the image detection sensor can have a broad range of configurations. However, with regard to rapid and precise detection of the respective workpiece surface, a development of the invention provides for at least one image detection sensor to have a camera and/or a colour measuring device. A CCD camera has proven especially advantageous in this regard, as the digital data obtained can be forwarded particularly simply and rapidly to a control means or the like. [0011]Within the scope of the present invention, the control means can also have a broad range of configurations. Nor is the possibility ruled out that the control means requires in some cases the involvement of an operator. However, with regard to the desired improved quality of the printed image, a development of the invention provides for the control means to be configured to analyse image data obtained by the image detection sensor, preferably at least with regard to the colour spectrum and/or defects and/or geometry and/or colour space (for example, RGB colour space) of each workpiece. [0012]Specifically if the at least one image detection sensor is used to detect the colour spectrum, but also to detect defects, it is important that a reproducible printed image is present at the moment of detection. Against this background, a development of the invention provides for the device further to have a drying means, in particular a UV drying means. This allows a predetermined drying state of the applied ink to be produced before the respective image detection is carried out. [0013]The above-described advantages of the device according to the invention can be achieved particularly advantageously by a method for patterning workpieces according to claim 7. It is in this case particularly preferred that the actual image data obtained through the image detection is compared with desired image data, in particular with regard to the colour spectrum and/or defects and/or geometry and/or colour space (for example, RGB colour space). This desired/actual data comparison can advantageously be utilised as a basis for improving the print quality, for example through the measures described hereinbefore. [0014]A development of the invention provides in this case for the control signals issued by the control means to the printing means to be corrected on the basis of the desired/actual data comparison in order to minimise deviation between the desired/actual data. The control means thus ensures, on the basis of the image detection performed by the image detection sensor, that the printed image which is actually produced approximates the desired printed image as closely as possible, i.e. optimum printed image quality is achieved. [0015]In order to achieve this, the control means can carry out a broad range of measures. However, it has proven particularly effective that the control means corrects, in accordance with a development of the invention, the control signals issued to the printing means in such a way that the intensity and/or the course of the control pulses to at least one nozzle of the printing means are altered. Control pulses can also be dispensed with altogether, i.e. the control signals issued by the control means to the printing means can be corrected in such a way that one or more nozzles are switched on or off. [0016]However, alternatively or additionally, the control means can also ascertain or decide that the determined deviation between the desired/actual data is caused by soiling of the print head, in particular the nozzles. In this case, a development of the method according to the invention provides for cleaning of the printing means to be carried out on the basis of the desired/actual data comparison in the event of a predetermined deviation between the desired/actual data. The control means can also decide, for example if corrective measures are unsuccessful, that basic maintenance of the device or even an emergency stop of the device is required. [0017]It should also be noted that the image detection sensor can operate continuously or discontinuously and that it can operate during normal operation of the device or else during check operation of the device in which, for example, predetermined test patterns are printed and detected by the image detection sensor. Furthermore, the image detection sensor can be positioned at any desired point of the device, wherein it has proven advantageous for at least one image detection sensor to be provided on the printing means. BRIEF DESCRIPTION OF THE DRAWINGS [0018]FIG. 1 is a schematic perspective view of a device for patterning workpieces according to an embodiment of the invention; [0019]FIG. 2 is a schematic partial plan view of the device shown in FIG. 1; [0020]FIG. 3 is a schematic, partially cut-away front view of the device shown in FIG. 1; Continue reading... Full patent description for Device for patterning workpieces Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Device for patterning workpieces patent application. Patent Applications in related categories: 20080170097 - Method of estimating alignment - an optical sensor scans along the scan axis over the first and second pattern elements, an analysis of the sensor output leading to estimating the alignment. each of the first and second pattern elements comprises a first and an associated second mark separated ... ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Device for patterning workpieces or other areas of interest. ### Previous Patent Application: Inkjet recorder Next Patent Application: Wiping apparatus for print head Industry Class: Incremental printing of symbolic information ### FreshPatents.com Support Thank you for viewing the Device for patterning workpieces patent info. 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